since you haven't broken his balance before you break his wrist, or he may be able to muscle out of it.

The way I learn indicates most of the techniques are intended to break one joint or another, not just Kote-Gaishi. This does not mean giving up on the Kuzushi, nor giving up your connection to Uke.
One does not have to coome instead of the other.

First achieve Kuzushi, then perform the technique correctly, in a manner which places your body against his weak point. And if you start to lose the connection, move on to another technique.
So if somethng got broken and no longer provides a connection, move up towards his center and continue, until he no longer threatens you.